Overexpression of CLDN16 in ovarian cancer is modulated by PI3K and PKC pathways.

Epithelial ovarian cancer (EOC) is the gynecological malignant tumor of poorest prognosis and higher mortality rate. Chemotherapy is the base of high-grade serous ovarian cancer (HGSOC) treatment; however, it favors the emergence of chemoresistance and metastasis. Thus, there is an urge to search for new therapeutic targets, such as proteins related to cellular proliferation and invasion. Herein, we investigated the expression profile of claudin-16 (CLDN16 protein and CLDN16 transcript) and its possible functions in EOC. In silico analysis of CLDN16 expression profile was performed using data extracted from GENT2 and GEPIA2 platforms. A retrospective study was carried out with 55 patients to evaluate the expression of CLDN16. The samples were evaluated by immunohistochemistry, immunofluorescence, qRT-PCR, molecular docking, sequencing, and immunoblotting assays. Statistical analyzes were performed using Kaplan-Meier curves, one-way ANOVA, Turkey posttest. Data were analyzed using GraphPad Prism 8.0. In silico experiments showed that CLDN16 is overexpressed in EOC. 80.0% of all EOC types overexpressed CLDN16, of which in 87% of the cases the protein is restricted to cellular cytoplasm. CLDN16 expression was not related to tumor stage, tumor cells differentiation status, tumor responsiveness to cisplatin, or patients' survival rate. When compared to data obtained from in silico analysis regarding EOC stage and degree of differentiation, differences were found in the former but not in the later, neither in survival curves. CLDN16 expression in HGSOC OVCAR-3 cells increased by 1.95-fold (p < 0.001), 2.32-fold (p < 0.001), and 6.57-fold (p < 0.001) via PKC, PI3K, and estrogen pathways, respectively. Altogether, our results suggest that despite the low number of samples included in our in vitro studies, adding to the expression profile findings, we provided a comprehensive study of CLDN16 expression in EOC. Therefore, we hypothesize that CLDN16 is a potential target in the diagnosis and treatment of the disease.

A case of aleukemic leukemia cutis after COVID-19 infection presenting as facial rash.

Aleukemic leukemia cutis (ALC) is a rare condition that is characterized by leukemic cells in the skin before presenting in the peripheral blood or bone marrow. We report a case of a 43-year-old woman who underwent assessment for bilateral facial nodules arising 1 month after COVID-19 infection. A punch biopsy specimen showed a malignant neoplasm primarily composed of immature blasts dissecting through the collagen in the dermis, concerning for myeloid sarcoma versus leukemia cutis. Bone marrow and blood specimens were negative for hematologic malignancy. The patient was appropriately treated with chemotherapy and is recovering well. This report highlights an interesting case of ALC following COVID-19 infection presenting as an isolated facial rash. Whether there is a true relationship between the patient's COVID-19 infection and her abrupt presentation of leukemia remains unclear, but we present this case regardless, in an effort to highlight a potentially unique association requiring further study.

Histopathologic and molecular characterization of BAP-1-inactivated melanoma.

BACKGROUND: BRCA1-associated protein 1 (BAP-1) is a deubiquitylase that functions as a tumor suppressor, regulating multiple cellular processes including cell cycle control, differentiation, cell death, and DNA repair. BAP-1-inactivated melanocytic tumors (BIMTs) have recently been described and are characterized by epithelioid cytomorphology, are often clonal in appearance, and typically do not recur or show malignant transformation on follow-up. AIM: To describe the histopathologic and molecular characterization of five cases of BAP-1-inactivated cutaneous malignant melanomas. METHODS: The archives at two separate institutions were retrospectively searched for tumors classified as melanoma with loss of BAP-1 via immunohistochemistry. Five cases were identified. These cases were classified as malignant melanoma based on cytomorphology, immunohistochemistry, and ancillary molecular testing. The clinical demographics were recorded, along with the histomorphologic features of each case. Genomic analysis for all cases was performed via OncoScan. RESULTS: The five reviewed cases consisted of two females and three males ranging from 67 to 74 years in age. Molecular characterization of each case was performed using OncoScan. Microarray assay showed that there was a complete deletion of 3p in all cases, BRAF V600E mutation in two cases, NRAS missense variant in one case, and loss of 9p in three cases. All cases showed malignant copy number alterations. CONCLUSIONS: Herein we describe five cases of BAP-1-inactivated melanomas confirmed by histomorphology and immunohistochemistry, all of which show malignant copy number profiles including loss of 3p. In addition, we provide a case of a likely BIMT showing progression to BAP-1-inactivated melanoma on a 16-year follow-up.

Secondary skin involvement in classic Hodgkin lymphoma: Results of an international collaborative cutaneous lymphoma working group study of 25 patients.

BACKGROUND: Cutaneous involvement by classic Hodgkin lymphoma (CHL) is an extraordinarily rare phenomenon in the current era. To date, no single large case series of cutaneous involvement by Hodgkin lymphoma has ever been reported in the literature. METHODS: A comprehensive search for cases designated "skin" and "Hodgkin" was performed at different institutions between 1990 and 2020. Twenty-five cases were identified, and each case was independently reviewed by at least three board-certified dermatopathologists and/or hematopathologists. RESULTS: All cases represented examples of systemic CHL with secondary skin dissemination. A single lesion, usually a tumor, nodule or infiltrative plaque was observed in 56% of cases and multiple lesions were present in 28% of cases. Most patients (86%-12/14) had a diagnosis of stage IV disease at first diagnosis. The interval between the clinical (first) diagnosis of HL and the development of skin lesions ranged between 6 and 108 months (average 33.75 months). Comprehensive histopathologic evaluation of these cases (at the initial diagnosis) revealed a diagnosis of classic HL not otherwise specified (NOS) in 60% of cases (15/25), nodular sclerosis type in 24% (6/25), mixed cellularity in 12% (3/25), and lymphocyte depleted in 4% (1/25). CONCLUSIONS: We provide documentation of a large series of CHL with secondary skin involvement in association with CHL with additional clinical, morphologic, and immunophenotypic features.

Novel SS18-NEDD4 gene fusion in a primary renal synovial sarcoma.

We report a primary renal synovial sarcoma with a novel gene fusion and unusual morphology. The patient was a 35-year-old female who was found to have a 5 cm hypocellular, myxoid spindle cell renal neoplasm that subtly permeated amongst native renal tubules. The tumor cells showed elongated hyperchromatic nuclei with ill-defined pale cytoplasm, lacking significant mitotic activity or necrosis. Based on its deceptively bland morphology, the differential diagnosis included mainly benign entities, such as metanephric stromal tumor, mixed epithelial stromal tumor (MEST), and myxoid peripheral nerve sheath tumors. A definitive diagnosis of synovial sarcoma was made only subsequently to RNA-sequencing, which revealed a novel SS18-NEDD4 gene fusion. These results were further confirmed by fluorescence in situ hybridization using custom design break-apart probes for both genes. This case illustrates the utility of targeted RNA-sequencing in the classification of challenging tumors with deceptive morphology and identification of novel gene fusion variants. Apart from the canonical SS18-SSX fusion, this is only the second alternative gene fusion variant described in synovial sarcoma to date, in addition to two cases harboring the SS18L1-SSX1 fusion.

Clear Cell Sarcoma With Cutaneous Presentation in a 4-Year-Old Boy.

We report a case of a 4-year-old Brazilian boy, who presented with an erythematous and painful nodule involving the skin of his left arm. Immunohistochemistry was performed for S100, SOX10, CD34, desmin, SMA, HMB-45, CD1a, and CD163, and fluorescence in situ hybridization for EWSR1 gene rearrangement using a break-apart probe was completed. Immunohistochemistry showed bland spindle cells with "floret-like" appearance simulating a giant cell fibroblastoma; tumor cells were positive for S100 and SOX10; neoplastic cells were negative for CD34, desmin, SMA, HMB-45, CD1a, and CD163; and fluorescence in situ hybridization showed an EWSR1 gene rearrangement. We report the youngest known case of cutaneous involvement of clear cell carcinoma at the age of 4.

EGFR Mutation Testing: Changing Patterns of Molecular Testing in Brazil.

BACKGROUND: In Brazil, cancer is the second most common cause of death. Most patients in resource-limited countries are diagnosed in advanced stages. Current guidelines advocate for EGFR mutation testing in all patients with metastatic adenocarcinoma. Tyrosine kinase inhibitors are recommended in patients with advanced or metastatic disease harboring sensitizing mutations. In Brazil, there are limited data regarding the frequency of EGFR testing and the changes in patterns of testing overtime. MATERIALS AND METHODS: This was an observational, retrospective study. We obtained deidentified data from a commercial database, which included 11,684 patients with non-small cell lung cancer treated between 2011 and 2016 in both public and private settings. We analyzed the frequency of EGFR mutation testing over time. We also directly studied 3,664 tumor samples, which were analyzed between 2011 and 2013. These samples were tested for EGFR mutations through an access program to tyrosine kinase inhibitors in Brazil. RESULTS: Overall, 38% of patients were tested for EGFR mutations; 76% of them were seen in the private sector, and 24% were seen in the public center. The frequency of testing for EGFR mutations increased significantly over time: 13% (287/2,228 patients) in 2011, 34% (738/2,142) in 2012, 39% (822/2,092) in 2013, 44% (866/1,972) in 2014, 53% (1,165/2,184) in 2015, and 42% (1,359/3,226) in 2016. EGFR mutations were detected in 25.5% of analyzed samples (857/3,364). Deletions in Exon 19 were the most frequent mutations, detected in 54% of patients (463/857). CONCLUSION: Our findings suggest that the frequency of EGFR mutation in this cohort was lower than that found in Asia but higher than in North American and Western European populations. The most commonly found mutations were in Exon 19 and Exon 21. Our study shows that fewer than half of patients are being tested and that the disparity is greater in the public sector. IMPLICATIONS FOR PRACTICE: These data not only indicate the shortage of testing but also show that the rates of positivity in those tested seem to be higher than in other cohorts for which data have been published. This study further supports the idea that awareness and access to testing should be improved in order to improve survival rates in lung cancer in Brazil.

Extraneuraxial Hemangioblastoma: Clinicopathologic Features and Review of the Literature.

Extraneuraxial hemangioblastoma occurs in nervous paraneuraxial structures, somatic tissues, and visceral organs, as part of von Hippel-Lindau disease (VHLD) or in sporadic cases. The VHL gene plausibly plays a key role in the initiation and tumorigenesis of both central nervous system and extraneuraxial hemangioblastoma, therefore, the underlying molecular and genetic mechanisms of the tumor growth are initially reviewed. The clinical criteria for the diagnosis of VHLD are summarized, with emphasis on the distinction of sporadic hemangioblastoma from the form fruste of VHLD (eg, hemangioblastoma-only VHLD). The world literature on the topic of extraneuraxial hemangioblastomas has been comprehensively reviewed with ∼200 cases reported to date: up to 140 paraneuraxial, mostly of proximal spinal nerve roots, and 65 peripheral, 15 of soft tissue, 6 peripheral nerve, 5 bone, and 39 of internal viscera, including 26 renal and 13 nonrenal. A handful of possible yet uncertain cases from older literature are not included in this review. The clinicopathologic features of extraneuraxial hemangioblastoma are selectively presented by anatomic site of origin, and the differential diagnosis is emphasized in these subsets. Reference is made also to 10 of the authors' personal cases of extraneuraxial hemangioblastomas, which include 4 paraneuraxial and 6 peripheral (2 soft tissue hemangioblastoma and 4 renal).

Solid pseudopapillary neoplasm (SPN) of the testis: Comprehensive mutational analysis of 6 testicular and 8 pancreatic SPNs.

BACKGROUND: Recently, we came with the theory of a possible relationship between a group of testicular and pancreatic tumors. We used one case of a pancreatic analogue solid pseudopapillary neoplasm of the testis composed partially of areas reminiscent of solid pseudopapillary neoplasm (SPN) of the pancreas and partially of structures identical to primary signet ring stromal tumor of the testis (PSRSTT) as a connecting link between these two entities. After demonstrating that PSRSTT and pancreatic analogue SPN of the testis share the same immunoprofile and genetic features characteristic for pancreatic SPN, we came to the conclusion that pancreatic analogue SPN of the testis and PSRSTT represent a morphological spectrum of a single entity and that both are related to the pancreatic SPN. DESIGN: The aim of this study is to present a series of 6 cases of testicular tumors, which lacked the signet ring cell component and were thus morphologically very similar to the SPN of the pancreas. The goal of this study is to compare the genetic background of these testicular tumors that are obviously related to the PSRSTT/pancreatic analogue SPN of the testis with the series of 8 pancreatic SPN. RESULTS: The mutational analysis revealed an oncogenic somatic mutation in the exon 3 of the CTNNB1 (ß-catenin) gene in all analyzable (5/6) testicular and all pancreatic (8/8) tumors. The immunoprofile (positivity with ß-catenin, CD10, vimentin, NSE, CD56, and negativity with inhibin, calretinin, chromogranin) was identical in all testicular and pancreatic tumors. CONCLUSION: This study expanded the morphological spectrum of the PSRSTT/pancreatic analogue SPN of the testis by adding 6 cases without the signet ring cell component. Considering the obvious analogy of PSRSTT/pancreatic analogue SPN of the testis/SPN of the testis and their relationship to the pancreatic SPN we propose the collective term "solid pseudopapillary neoplasm of the testis" for these tumors. The mutational profile of the SPN of the testis and pancreas was the same in both groups of tumors which we consider as a final proof that SPN of the testis is identical to the SPN of the pancreas.

miR-17-92 cluster components analysis in Burkitt lymphoma: overexpression of miR-17 is associated with poor prognosis.

Burkitt lymphoma (BL) is an aggressive B cell lymphoma characterized by the reciprocal translocation of the c-Myc gene with immunoglobulin genes. Recently, MYC has been shown to maintain the neoplastic state via the miR-17-92 microRNA cluster that suppresses chromatin regulatory genes and the apoptosis regulator Bim. However, the expression and prognostic impact of miR-17-92 members in pediatric BL (pBL) are unknown. Therefore, we investigated miR-17, miR-19a, miR-19b, miR-20, and miR-92a expression and prognostic impact in a series of 41 pBL samples. In addition, Bim protein expression was evaluated and compared to miR-17, miR-19a, miR-19b, miR-20, and miR-92a levels and patient outcomes. The expression of miR-17-92 members was evaluated by qPCR and Bim protein by immunohistochemistry. Log-rank test was employed to assess prognostic impact. We found that upregulated expression of miR-17 and miR-20a correlates with lack of pro-apoptotic Bim expression. Patients bearing tumors with upregulated miR-17 displayed decreased overall survival (OS), and multivariate analysis revealed that miR-17 was a significant predictor of shortened OS. Using hairpin inhibitors, we showed that inhibition of miR-17 resulted in enhanced Bim expression in a BL cell line overexpressing the miR-17-92 cluster. Our results describe for the first time miR-17, miR-19a, miR-19b, miR-20a, and miR-92a expression profiles in pBL. The prognostic impact of miR-17 should be validated in a larger series, and may provide new therapeutic avenues in the era of anti-miRNA therapy research. Additional functional studies are further required to understand the specific role of miR-17-92 cluster members in BL.

Desmoplastic melanoma: an updated immunohistochemical analysis of 40 cases with a proposal for an additional panel of stains for diagnosis.

Desmoplastic melanoma (DM) is histologically characterized by a proliferation of spindle melanocytes dispersed in a collagenous stroma that can be mistaken for a variety of neoplasms. The purpose of this study was to analyze 40 cases of DM with a comprehensive panel of immunohistochemical markers (KBA.62, p16, Ezrin, WT-1, MITF-1, SOX-10, CD117, SOX-2, nestin, PNL2, p75, MART-1, gp100 and S100p) to obtain a more complete understanding of the potential use of these antibodies in the diagnosis of DM. We found that all cases of DM expressed p16, WT-1, SOX-10, nestin and S100p and 95% of cases expressed p75. There was variable expression with Ezrin, SOX-2, KBA.62, MART-1 and HMB-45. Most DMs did not express MITF-1, PNL2 and CD117. Conditions that may enter in the histologic differential diagnosis of DM, including dermal scars, fibromatosis and dermatofibromas were also studied. Nearly all control cases also stained positive for p16 but were negative for WT1, SOX10, nestin, p75 and S-100p, as well as for most of the other markers tested. We conclude that a panel of S-100p, WT1, SOX10, p75 and nestin may constitute the optimal panel with the most sensitive and specific combination of immunostain available for the diagnosis of DM.

Lipophyllodes of the breast. A reappraisal of fat-rich tumors of the breast based on 22 cases integrated by immunohistochemical study, molecular pathology insights, and clinical follow-up.

We have studied 22 cases of mammary lipophyllodes tumors (LPT), analyzing their clinicopathologic features along with available follow-up. All cases were tested for cytokeratins, S100 protein, and MDM2, and in selected cases for estrogen receptor, smooth muscle actin, bcl2, desmin, and myogenin. Patients were women aged 21 to 69 years (average, 45 years), and LPT size ranged from 1.6 to 30 cm (average, 9.7 cm). Microscopically, LPT segregated as follows: atypical lipoma-like tumor/well-differentiated liposarcoma (ALT/WDL), 8 cases; myxoid, 6; and pleomorphic/poorly differentiated/round cell, 8, including a case of dedifferentiated liposarcoma. Immunohistochemistry studies showed focal positive staining for S100 and CD34 in most ALT/WDL, and desmin and myogenin in 2 cases with evidence of rhabdomyoblastic differentiation. MDM2 positivity was focally seen in 1 case. Follow-up was available in 8 cases. Multiple recurrent tumors were seen in 2 patients, and metastatic disease to the lung was seen in 2 patients. In 4 patients with a follow-up between 2 and 15 years there was no evidence of recurrent or metastatic disease. Patients with ALT/WDL (2/2) were alive with no evidence of disease; 2 of 4 patients with myxoid liposarcoma component experienced tumor recurrence, whereas pleomorphic liposarcoma LPT pursued a less favorable course although only 1 patient died of the condition. Absence of MDM2 reactivity in most cases seems not as meaningful as in fatty tumors of somatic soft parts.

The spectrum of rare morphological variants of cutaneous epithelioid angiosarcoma.

AIMS: Unusual cytoplasmic alterations have recently been reported in poorly differentiated cutaneous angiosarcoma, making an accurate diagnosis challenging. As these tumours remain poorly documented, we aimed to study their clinicopathological characteristics more comprehensively. METHODS AND RESULTS: Six cutaneous angiosarcomas with unusual cytoplasmic alterations were identified from referral files. All tumours arose as nodules or plaques (range: 05-195 mm) on sun-damaged skin of the head and neck of elderly males (median age: 76.5 years). Histologically, the tumours were composed of enlarged epithelioid cells showing prominent signet ring (n = 3), foam (n = 2) or granular cell (n = 1) change. Vasoformative elements were only focally noted. By immunohistochemistry, all tumours expressed CD31 and avian v-ets erythroblastosis virus E26 oncogene homologue (ERG). Foam cell change was associated with additional expression of CD68 and CD163. Follow-up (median: 8 months) showed death from disease (n = 1), death from a gastrointestinal bleed (n = 1), and a cutaneous metastasis (n = 1). Only two patients are alive with no evidence of disease. CONCLUSIONS: Our findings outline the morphological spectrum of cytoplasmic change in cutaneous angiosarcoma. Awareness and a high degree of suspicion in the context of tumours affecting sun-damaged skin of the elderly are necessary to direct appropriate immunohistochemical work-up with inclusion of the endothelial cell markers CD31 and ERG.

Identification of LMO2 transcriptome and interactome in diffuse large B-cell lymphoma.

LMO2 regulates gene expression by facilitating the formation of multipartite DNA-binding complexes. In B cells, LMO2 is specifically up-regulated in the germinal center (GC) and is expressed in GC-derived non-Hodgkin lymphomas. LMO2 is one of the most powerful prognostic indicators in diffuse large B-cell (DLBCL) patients. However, its function in GC B cells and DLBCL is currently unknown. In this study, we characterized the LMO2 transcriptome and transcriptional complex in DLBCL cells. LMO2 regulates genes implicated in kinetochore function, chromosome assembly, and mitosis. Overexpression of LMO2 in DLBCL cell lines results in centrosome amplification. In DLBCL, the LMO2 complex contains some of the traditional partners, such as LDB1, E2A, HEB, Lyl1, ETO2, and SP1, but not TAL1 or GATA proteins. Furthermore, we identified novel LMO2 interacting partners: ELK1, nuclear factor of activated T-cells (NFATc1), and lymphoid enhancer-binding factor1 (LEF1) proteins. Reporter assays revealed that LMO2 increases transcriptional activity of NFATc1 and decreases transcriptional activity of LEF1 proteins. Overall, our studies identified a novel LMO2 transcriptome and interactome in DLBCL and provides a platform for future elucidation of LMO2 function in GC B cells and DLBCL pathogenesis.

Geographic differences in the distribution of molecular subtypes of breast cancer in Brazil.

BACKGROUND: To compare the distribution of the intrinsic molecular subtypes of breast cancer based on immunohistochemical profile in the five major geographic regions of Brazil, a country of continental dimension, with a wide racial variation of people. METHODS: The study was retrospective observational. We classified 5,687 invasive breast cancers by molecular subtype based on immunohistochemical expression of estrogen-receptor (ER), progesterone-receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 proliferation index. Cases were classified as luminal A (ER and/or PR positive and HER2 negative, Ki-67 < 14%), luminal B (ER and/or PR positive, HER2 negative, and Ki-67 > 14%), triple-positive (ER and/or PR positive and HER2 positive), HER2-enriched (ER and PR negative, and HER2- positive), and triple-negative (TN) (ER negative, PR negative, and HER2- negative). Comparisons of the ages of patients and molecular subtypes between different geographic regions were performed. RESULTS: South and Southeast regions with a higher percentage of European ancestry and higher socioeconomic status presented with the highest proportion of luminal tumors. The North region presented with more aggressive subtypes (HER2-enriched and triple-negative), while the Central-West region predominated triple-positive carcinomas. The Northeast--a region with a high African influence--presented intermediate frequency of the different molecular subtypes. The differences persisted in subgroups of patients under and over 50 years. CONCLUSIONS: The geographic regions differ according to the distribution of molecular subtypes of breast cancer. However, other differences, beside those related to African ancestry, such as socioeconomic, climatic, nutritional, and geographic, have to be considered to explain our results. The knowledge of the differences in breast cancer characteristics among the geographic regions may help to organize healthcare programs in large countries like Brazil with diverse economic and race composition among different geographic regions.

Microinvasive adenocarcinoma of the cervix in a young woman vaccinated against human papillomavirus: the screening must be continued.

OBJECTIVE: This report describes a case that illustrates the limitations of the vaccination screening process for human papillomavirus (HPV) infection. CASE: We report an unexpected microinvasive adenocarcinoma of the cervix arising in a young woman vaccinated against HPV as part of a clinical trial 6 years previously and followed up annually by cytology. In January 2012, at age 23 years, the patient received a cytological result of atypical squamous cells, cannot exclude high-grade cervical squamous intraepithelial lesion, and colposcopy showed slight abnormalities. Biopsy revealed an adenocarcinoma in situ. Conization of the cervix was performed, and the diagnosis was microinvasive adenocarcinoma. Polymerase chain reaction and immunohistochemical study of conization material showed positivity for HPV-18 L1, p16, and Ki-67. Retrospective analysis of the clinical trial information revealed that 7 HPV tests had been performed, and all were positive for HPV-18, including the sample collected before the first vaccination. CONCLUSIONS: HPV-18 was present in the cervix before vaccination. Persistent detection of HPV-18 should be considered an important factor in treatment planning. This case demonstrates the need to vaccinate women before their first sexual contact and highlights the need for keeping adequate screening even in vaccinated individuals.

Benign cervical schwannoma with tracheal invasion.

Schwannomas commonly develop in the cervical region, 25% - 45% of cases are diagnosed in this anatomical region. Tracheal neurogenic tumors are exceedingly rare and can be misdiagnosed as invasive thyroid carcinomas or other infiltrating malignancies when present at the level of the thyroid gland. Here, we present a case of synchronous benign cervical schwannoma with tracheal invasion and papillary thyroid carcinoma in a patient who was initially hospitalized for COVID-19. The patient presented with dyspnea that was later found to be caused by tracheal extension of a cervical tumor. Surgical excision was performed, and the surgical team proceeded with segmental tracheal resection, removal of the cervical mass, and total thyroidectomy. The specimen was sent for pathological analysis, which revealed synchronous findings of a benign cervical schwannoma with tracheal invasion and papillary thyroid carcinoma. The literature on this subject, together with the present case report, suggests that neurogenic tumors should be included in the differential diagnosis of obstructing tracheal cervical masses. Surgical excision is the first-line of treatment for benign cervical schwannomas.

Tubulocystic Carcinoma of Bile Ducts: A Distinct Type of Cholangiocarcinoma Associated With Adenofibroma-type Lesions.

A type of cholangiocarcinoma (CCA) characterized by peculiar histologic patterns and underlying adenofibromatous lesions has been reported in the literature mostly as individual case reports. This study aims to further clarify the defining characteristics of this spectrum of lesions. Clinicopathologic analysis of 8 biliary tumors with tubulocystic architecture arising in the background of adenofibroma-type lesions was performed. Three of these were also investigated with next-generation sequencing with a 174 genes panel. The patients were 5 males and 3 females, with a mean age of 64.6. All tumors were intrahepatic except for one perihilar that protruded into soft tissues. The mean size was 4.4 cm. At histology, all cases showed a peculiar and cytologically bland tubulocystic pattern that closely resembled tubulocystic-type kidney cancers, including back-to-back microcystic units that formed relatively demarcated nodules, and occurring in the background of adenofibromatous lesions. One case showed perineural invasion by otherwise deceptively benign-appearing microcystic structures, one had areas transitioning to intraductal tubulopapillary neoplasm, and 3 cases harbored more conventional small-duct CCA foci. In those 3 cases, both the tubulocystic and conventional CCA components were investigated by next-generation sequencing separately, and they shared the molecular alterations, including recurrent mutations in chromatin remodeling genes, such as ARID1A, BAP1, and PBRM1, and the actionable FGFR2-MCU fusion gene. In the limited follow-up, all but one were alive and free of disease after surgical resection. In conclusion, we described a distinct entity of CCA with specific histo-molecular features, for which we propose the designation of tubulocystic carcinoma of bile ducts.

Follicular lymphoma in young adults: a clinicopathological and molecular study of 200 patients.

Follicular lymphoma is clinically heterogenous, and therefore necessitates the identification of prognostic markers to stratify risk groups and optimize clinical management. It is relatively rare in patients younger than 40 years, and the clinicopathologic characteristics and biological behavior in this age group are poorly understood. In the current study, samples from a cohort of 200 patients between 19 and 40 years were evaluated retrospectively with respect to clinical, histologic, and genetic features. These were then correlated with clinical outcome. The median age at presentation was 35 years with a slight female prepoderance (56%). Most of the cases are presented with nodal disease (90%). Concomitant follicular lymphoma and diffuse large B-cell lymphoma were observed in 7 (4%) patients. Immunohistologic studies showed the expression of CD10 (91%), BCL6 (97%), BCL2 (95%), MUM1/IRF4 (12%), MDM2 (17%), and CD23 (25%). BCL2 rearrangement was present in 74%, and BCL6 in 20%. The estimated overall survival of patients was 13 years (mean). The presence of anemia, elevated lactose dehydrogenase, bone marrow involvement, and high-risk follicular lymphoma international prognostic index correlated with adverse overall survival. Our findings revealed that follicular lymphoma in young adults demonstrate similarities with that of older adults, including the frequency of presentation at various anatomic sites, grade, and adverse prognostic factors.